A study on the transfer matrix and dynamical characteristics of flexible pipe bend

Abstract

Much of the noise originates from pressure and flow fluctuations generated by pump. These pressure fluctuations are transmitted along the hydraulic lines and cause unbalanced forces at pipe bends and changes of section. The flexible pipe bend, a recently developed flexible component of pipe, can usually reduce thermal expanding reaction and endure large and complex stress and strain arising from different movements and also due to complex geometry. The rubber hose wall can conduct oscillating longitudinal forces that may interact with fluid waves inside. Up to now, little attention has been paid to study its performances of vibration damping and noise attenuation in pipeline. The transfer matrix, an effective numerical method, is applied to analyze and evaluate the transfer performance of flexible pipe bend. However, because of its geometrical complexity, it is difficult to directly calculate the transfer matrix of the flexible pipe bend. In this paper, the flexible pipe bend is divided into several parts, each of which can be considered as a short straight pipe. Through the conversion between the global coordinate system and local coordinate system, a transfer matrix of the flexible pipe bend is derived and applied, which provide a practical method to analyze the frequency, modal and response of the flexible pipe bend.